This invention relates to an improvement to check valves of the type generally shown in Griffith U.S. Pat. No. 2,594,641. Such check valves have a valve body which defines an axially oriented through passageway, and an annular valve seat disposed around the passageway. A groove extends around at least part of the passageway, and a centering element is mounted in the groove to extend across the passageway and to support a central guide. A valve pin is mounted to slide in the central guide between a sealing position, in which the valve pin seals against the valve seat to close the through passageway, and an open position, in which the valve pin is spaced from the valve seat to permit flow through the passageway.
In the past, it has been suggested to use check valves of this type in automotive air conditioning lines. One such application requires the valve body to be shaped to engage a wrench so the valve body can be screwed into and removed from the air conditioning system. In addition, in this application the valve body must be shaped to engage a quick disconnect coupler, used in the automotive industry to connect a Freon charging line to the check valve body.
One obvious solution to this requirement is to provide a conventional annular quick disconnect shoulder on the valve body which is circular in cross section, and to provide an additional raised ridge on the check body to define wrench flats. The use of two separate annular ridges to perform the quick disconnect engaging function and the wrench engaging function may unnecessarily increase the overall length of the valve body and therefore the size and cost of the check valve.